Mixers are widely used in radio technology. A harmonic mixer, sometimes called a sampling mixer, mixes a signal with a pulse sequence representing the oscillator signal, wherein the pulse sequence has a fundamental frequency equal to a desired frequency translation frequency, and wherein switches can be used in the mixer. This has advantages in design in sense of power consumption and ability to operate at high frequencies. Due to the properties of the pulses, harmonics are generated. For alleviating this, and still keep the advantages of the harmonic mixer, the mixing can be performed at several mixer unit cells and the output from these are added, sometimes with opposite signs, i.e. a subtraction, to form an aggregate output signal more resembling the one of a time-continuous mixing with a sinusoid oscillator signal. US 2009/0280762 A1 discloses a high-order harmonic rejection mixer using a current steering technique. The mixer generates a sinus-like signal by an input current generation unit generating and outputting an input current corresponding to an input signal, a first path circuit unit including a plurality of transistors having sources connected in common to the input current generation unit, a second path circuit including a plurality of transistors having sources connected in common to the input current generation unit, and a load unit connected to drains of the transistors of the first path circuit, while the drains of the transistors of the second path circuit are connected to ground. A local oscillator signal is phase shifted in steps corresponding to the plurality of transistors in the paths and are connected to the gates of the transistors with in-phase polarity to the transistors of the first circuit path and with opposite phase polarity to the transistors of the second circuit path. The transconductance of each of the transistors of the first path circuit is determined such that current passing through the transistors are turned on or off according to the phase-shifted oscillator signal to resemble a sinusoidal waveform.
Complex mixers provide a division of the mixed signal in an in-phase down-converted signal and a quadrature-phase down-converted signal. This can be provided by arranging one mixer arrangement for the in-phase purpose, and one mixer arrangement for the quadrature-phase purpose, with oscillator signals thereto arranged in proper phase.
Mixers arranged to deal with two or more carriers are normally arranged by multiplying the number of mixers in the arrangements accordingly.
When all the considerations above aggregates in a mixer design, the amount of circuitry rapidly expands. In circuit design, this requires a considerable layout size, which may cause one or more of the following problems: cost, size, power consumption, and signal path considerations (due to high-frequency issues).
It is therefore a desire to alleviate such problems.